CHE-06 Solved Question Paper for the June 2026 term-end exam is the official IGNOU paper with every question answered by our chemistry team, in the step-by-step mechanism format the B.Sc. examiners mark against. This page opens two complete answers so you can check the quality, and lists the other six questions exactly as they were printed.
Key facts for the IGNOU CHE-06 June 2026 solved question paper
- Course code: CHE-06
- Code printed on the paper: CHE-006 (same course; the June 2026 paper prints the three-digit form)
- Subject: Organic Reaction Mechanism
- Programme: Bachelor of Science (B.Sc.), programme code BSC, Bachelor's Degree Programme chemistry elective, School of Sciences
- Credits: 4 credits
- Blocks and units: 4 blocks, 16 units
- Maximum marks and duration: 50 marks, 2 hours
- Questions in the paper: 8 questions of 10 marks each (16 parts of 5 marks); answer any five
- Printed vs attempted marks: 80 marks printed, 50 attempted
- Internal choice: Q4(a) any one of two, Q7(b) any two of four, Q8(b) any one of three
- Printed word limit: none; about 100 to 120 words plus the key equation for a 5-mark part, worked out from the time available
- Language: bilingual, English followed by Hindi
- Solved samples on this page: 2 (Q1 and Q3)
- Questions in the full file: All 8, including the 6 not answered on this page
What the CHE-06 Solved Question Paper June 2026 covers
CHE-06 Organic Reaction Mechanism is the 50-mark organic chemistry elective in IGNOU's B.Sc. under the Bachelor's Degree Programme, and this file solves its June 2026 term-end paper in full. The course is about why reactions happen the way they do: which bond breaks, where the electrons go and which intermediate decides the product.
The June 2026 paper carries 8 questions, each split into an (a) and a (b) part of 5 marks. You answer any five. That makes 16 separate pieces of chemistry, from carbenes and Markovnikov's rule to polymers, detergents and three named rearrangement or redox reactions.
Students who search for the CHE-06 Question Paper usually need two things at once: the exact questions IGNOU asked, and answers they can trust. This page gives you the first in full and the second for two questions, so you can judge the writing before you ask for the rest.
8 questions × 10 marks = 80 marks printed. You write any 5 = 50 marks, so 3 questions can be skipped. 120 minutes ÷ 5 = 24 minutes per question, 12 minutes per 5-mark part.
CHE-06 sample solved questions from the June 2026 paper
Q1 and Q3 of the June 2026 CHE-06 paper are answered in full below; Q2 and Q4 to Q8 are listed as printed and are answered only in the full file. Both sample answers are written for revision, so each part runs to about 210 to 250 words, more than the 12 minutes for a 5-mark part allows. In the hall, write to the length in the table under the paper pattern.
Carbenes: 3 of 5 earlier papers Blocks 3 and 2 5 + 5 marks
Question 1 (10 marks)
Part (a) (5 marks)
1. (a) What are carbenes? Write the reaction of dibromocarbene with cis-2-butene? 5
Answer. Carbenes are neutral, highly reactive intermediates in which a carbon atom has only two bonds and two non-bonding electrons, giving six electrons in its valence shell. The general formula is RβC:, and the simplest is methylene, :CHβ. Because the carbon is electron-deficient, carbenes behave mainly as electrophiles and are too short-lived to isolate.
Carbenes exist in two forms. In a singlet carbene the two non-bonding electrons are paired in one spΒ² orbital, the p orbital is empty and the species is bent. In a triplet carbene the two electrons are unpaired in separate orbitals, which makes it behave like a diradical. Halogen-substituted carbenes such as :CBrβ prefer the singlet state.
Generation of dibromocarbene. Bromoform is treated with a strong base such as potassium tert-butoxide. The base removes the proton to give the tribromomethyl anion, which then loses a bromide ion (Ξ±-elimination):
CHBrβ + (CHβ)βCOβ» β β»CBrβ + (CHβ)βCOH; β»CBrβ β :CBrβ + Brβ»
Reaction with cis-2-butene. Singlet :CBrβ adds across the C=C double bond in a single concerted step, forming both new CβC bonds at the same time. The product is a cyclopropane:
cis-CHβCH=CHCHβ + :CBrβ β cis-1,1-dibromo-2,3-dimethylcyclopropane
Because the addition is concerted, the two methyl groups have no chance to rotate, so the cis geometry of the alkene is kept in the product (stereospecific syn addition). Trans-2-butene, under the same conditions, gives only the trans-dimethyl product. This retention of geometry is the standard evidence that dibromocarbene reacts as a singlet carbene.
Part (b) (5 marks)
1. (b) Why are aldehydes more reactive than ketones towards nucleophilic addition reactions? 5
Answer. In nucleophilic addition, a nucleophile attacks the partially positive carbonyl carbon and the carbon changes from trigonal planar (spΒ²) to tetrahedral (spΒ³). Aldehydes (RCHO) react faster than ketones (RβCO) for two reasons, one electronic and one steric.
- Electronic effect. Alkyl groups release electrons through the +I effect and hyperconjugation. An aldehyde has one alkyl group and one hydrogen on the carbonyl carbon, while a ketone has two alkyl groups. The ketone's carbonyl carbon is therefore less positive and attracts the nucleophile less strongly.
- Steric effect. When the nucleophile adds, the groups on the carbonyl carbon are pushed closer together in the tetrahedral product. A small hydrogen atom causes little crowding, but two alkyl groups crowd both the approach of the nucleophile and the tetrahedral intermediate, raising the energy of the transition state.
The resulting order of reactivity is HCHO > CHβCHO > CHβCOCHβ. For example, acetaldehyde reacts readily with HCN and with sodium bisulphite, while bulky ketones such as diethyl ketone react only slowly or not at all with sodium bisulphite. Aromatic aldehydes and ketones are less reactive still, because the ring delocalises the positive charge on the carbonyl carbon.
Hall length: if time is short, keep in (a) the definition, one line on the singlet state, both equations and the retention-of-geometry line; in (b) the two numbered effects and the reactivity order.
HBr with propene: 2 of 5 earlier papers Block 2 5 + 5 marks
Question 3 (10 marks)
Part (a) (5 marks)
3. (a) How do aldehydes react with water? Which of the following compounds would make [the] most stable hydrate and why? ClβCCOCClβ, CHβCHβCOCHβ, CHβCHO 5
Answer. Aldehydes add water across the C=O bond to form a hydrate, also called a gem-diol, in which two βOH groups sit on the same carbon. The reaction is a reversible nucleophilic addition and is catalysed by both acid and base:
RCHO + HβO β RCH(OH)β
Mechanism (base catalysed). The hydroxide ion attacks the carbonyl carbon to give a tetrahedral alkoxide intermediate, which takes a proton from water to give the gem-diol and regenerate OHβ». In acid, the carbonyl oxygen is protonated first, making the carbon more electrophilic so that neutral water can attack.
The position of the equilibrium depends on the carbonyl compound. Formaldehyde exists almost completely as its hydrate in water, acetaldehyde is roughly half hydrated, and simple ketones such as acetone are hydrated only to a very small extent. Groups that withdraw electrons destabilise the C=O form and push the equilibrium towards the hydrate.
Most stable hydrate: ClβCCOCClβ (hexachloroacetone). Its six chlorine atoms exert a strong βI effect, which makes the carbonyl carbon very electron-deficient and the C=O form unstable, so the gem-diol is strongly favoured. The same effect explains why chloral (ClβCCHO) forms the stable, isolable chloral hydrate.
The expected order of hydrate stability is ClβCCOCClβ > CHβCHO > CHβCHβCOCHβ. Acetaldehyde has only one weakly donating methyl group. Butanone has two electron-releasing alkyl groups and more steric crowding, so its carbonyl form is the most stable of the three and its hydrate forms least.
Part (b) (5 marks)
3. (b) What is Markovnikoff's [Markovnikov's] rule? Describe the mechanism of the reaction of HBr with propene. 5
Answer. Markovnikov's rule states that when an unsymmetrical reagent HX adds to an unsymmetrical alkene, the hydrogen atom goes to the double-bonded carbon that already carries more hydrogen atoms, and X goes to the carbon with fewer hydrogen atoms. In modern terms, the reaction proceeds through the more stable carbocation.
CHββCH=CHβ + HBr β CHββCHBrβCHβ (2-bromopropane, major product)
Step 1: formation of the carbocation (slow step). The Ο electrons of propene attack the hydrogen of HBr, and bromide leaves as Brβ». If HβΊ adds to the terminal CHβ carbon, a secondary carbocation CHββCβΊHβCHβ forms. If it adds to the middle carbon, a primary carbocation CHβCHβCHββΊ would form.
The secondary carbocation is more stable because two methyl groups release electrons to it through the +I effect and through hyperconjugation with six CβH bonds. The primary cation has far less of this stabilisation, so the reaction goes almost entirely through the secondary carbocation.
Step 2: attack of bromide (fast step). Brβ» attacks the positively charged carbon of CHββCβΊHβCHβ to give 2-bromopropane. This is the Markovnikov product. In the presence of peroxides, HBr adds by a free radical chain instead and gives 1-bromopropane, which is the anti-Markovnikov (Kharasch) product.
Hall length: if time is short, keep in (a) the hydrate equation, the hexachloroacetone reason and the stability order; in (b) the rule, the equation and the two steps with the secondary-carbocation reason.
Questions answered only in the full file
The six questions below appear exactly as printed in the June 2026 paper. Their answers, with full mechanisms, are in the paid file only.
2. (a) How will you convert? 5
(i) p-nitrotoluene to 2, 4-dinitrobenzoic acid
(ii) Benzyl alcohol to benzaldehyde.
(b) Complete the following reactions: 5
(i) CβHβ βNOβ with AlClβ / CHβCl β
(ii) CβHβ βCl with HNOβ/HβSOβ β X, then NHβ β Y
(iii) CβHβ CHO + CHβCHO with Base β
(iv) Cyclohexanone oxime (CβHββ=NβOH) with HβSOβ β
4. (a) Write the product formed in any one of the following reactions. Explain with the help of the mechanism involved: 5
(i) CHβCOOCβHβ with CβHβ Oβ»NaβΊ / CβHβ OH β
(ii) CHβ CHβ CHβ + Clβ with hΞ½ β
(b) What are cycloaddition reactions? Why is thermally induced 2 + 2 cycloaddition reaction is [sic] symmetry forbidden? 5
5. (a) What are stereoselective and stereo-specific reactions? Give one example in each case. 5
(b) How are carbonyl compounds reduced to alkanes in acidic and alkaline medium? Discuss with appropriate example. 5
6. (a) Starting from ethylacetoacetate [ethyl acetoacetate] how will you prepare (i) Succinic acid (ii) 2βPentanone. 5
(b) Methyl group is ortho and para directing in electrophilic aromatic substitution reactions whereas trichloro-methyl group is meta directing. Justify the statement. 5
7. (a) What are copolymers and homopolymers? Classify the following polymers as chain growth and step growth polymers: 5
(i) Polyethylene (ii) Caprolactam (iii) Terelene [Terylene] (iv) Teflon
(b) Write short notes on any two of the following: 5
(i) Synthetic detergents
(ii) Oxidation of aldehydes
(iii) Analgesics
(iv) Acid dyes
8. (a) Complete the following reactions: 5
(i) (CHβ)βCOβ»NaβΊ + CHβCHβBr β
(ii) CHβCH = CHβ with HβO/HβSOβ β
(iii) CHβCH = CHCHO with NaBHβ β
(iv) HC β‘ CH with NaNHβ/NHβ, CHβCHβBr β
(v) Oxetane (four-membered ring containing O) with CHβMgBr, HβO/HβΊ β
(b) Discuss any one of the following giving the mechanism of the reaction: 5
(i) Beckmann reaction
(ii) BenzilβBenzilic acid reaction
(iii) Cannizzaro reaction
Structures drawn as diagrams in the printed paper (the benzene rings in Q2(b) and the rings in Q2(b)(iv) and Q8(a)(v)) are written here in linear form; the wording is unchanged.
CHE-06 Organic Reaction Mechanism blocks and units
CHE-06 is taught in 4 blocks and 16 units, and every block is tested in the June 2026 paper. The table maps each block to the topics it teaches and the June 2026 parts that come from it.
| Block | Units | Topics taught in the block | June 2026 parts from this block |
|---|---|---|---|
| Block 1: Basic Concepts and Substitutions | Unit 1 Reaction Mechanism: Introduction; Unit 2 Kinetic and Mechanism of Reaction; Unit 3 Aliphatic Nucleophilic Substitution; Unit 4 Aromatic Electrophilic Substitution | Bond heterolysis and homolysis, SN1 and SN2 kinetics, nitronium ion attack and the arenium intermediate in aromatic substitution | Q2(b)(i) and (ii), Q6(b) directing effect of βCHβ against βCClβ, Q8(a)(i) alkoxide with ethyl bromide |
| Block 2: Addition and Elimination | Unit 5 Addition to Carbon-Carbon Multiple Bond System; Unit 6 Nucleophilic Addition to Carbonyl Compounds; Unit 7 Elimination Reactions; Unit 8 Oxidation and Reduction | Markovnikov and peroxide addition, nucleophilic addition to C=O, Clemmensen and Wolff-Kishner style reductions | Q1(b), Q3(a), Q3(b), Q5(a), Q5(b), Q2(a), Q2(b)(iii), Q8(a)(ii) and (iii), Q7(b)(ii) oxidation of aldehydes |
| Block 3: Reaction Intermediates and Molecular Rearrangements | Unit 9 Carbenes, Nitrenes and Benzynes; Unit 10 Free Radicals; Unit 11 Molecular Rearrangements; Unit 12 Pericyclic Reaction | Carbenes and their cyclopropane additions, radical halogenation of alkanes, oxime and benzil rearrangements, pericyclic symmetry rules | Q1(a), Q4(a)(ii), Q4(b), Q2(b)(iv), Q8(b) |
| Block 4: Photochemistry and Synthetic Methods | Unit 13 Organic Photochemistry; Unit 14 [VERIFY: title, Strategy of Organic Synthesis or Chemistry of Carbonyl Compounds]; Unit 15 Case Study of some Chemicals of Daily Use-I; Unit 16 Case Study of some Chemicals of Daily Use-II | Acetoacetic ester synthesis, chain-growth against step-growth polymers, detergents, analgesics and acid dyes | Q6(a), Q7(a), Q7(b)(i), (iii) and (iv), Q4(a)(i), Q8(a)(iv) and (v) |
Block 4 looks like the soft block, and in this paper it is. Q7 alone is ten marks of polymers, detergents, analgesics and dyes that need almost no curved arrows. If you want unit-wise notes before you attempt the paper, our CHE-06 Study Material page has them block by block.
Block share of the 80 printed marks: Block 1 about 8.5, Block 2 about 33.25, Block 3 about 21.25, Block 4 about 17 (counting Q4(a) under Block 3 and Q7(b) under Block 4). Block 2 carries 42% of the paper from 4 units; Block 1 only 11%.
CHE-06 question paper pattern and marks distribution
The June 2026 CHE-06 paper is a 2-hour, 50-mark paper with 8 questions of 10 marks each, of which you answer any five. Every question has two 5-mark parts, and three questions carry an internal choice.
| Feature | June 2026 detail | What it means when you write |
|---|---|---|
| Duration and marks | 2 hours, 50 marks | About 24 minutes per 10-mark question, so each 5-mark part gets around 12 minutes |
| Choice of questions | Answer any five of eight | Skip the three questions whose mechanisms you cannot draw from memory |
| Part structure | Each question has an (a) and a (b) part of 5 marks | You can mix a strong part with a weaker one, but both must be attempted to reach 10 |
| Internal choice | Q4(a) any one of two, Q7(b) any two of four, Q8(b) any one of three | Q7(b) and Q8(b) let you pick the reactions you have practised most |
| Reaction-completion items | Q2(b) has four reactions and Q8(a) has five | Each item is worth about one mark, so write the product structure and its name |
| Language | Bilingual, English followed by Hindi | Write in one medium throughout; chemical names and formulae stay the same |
The same pattern runs through older papers too, so the IGNOU CHE-06 Question Paper from June 2026 is a fair model for the next session. To compare it with earlier years, see the BSC Question Paper collection for the programme.
Choice rule: any 5 of 8 gives 56 possible combinations. Only five questions count, so a sixth answer earns nothing and costs you 24 minutes.
How much to write. The paper prints no word limit, so the length below is worked out from time. A student writing by hand keeps up about 11 to 12 words a minute, and a mechanism paper needs extra minutes for structures and arrows.
| Marks | Where it appears | Minutes | What to write |
|---|---|---|---|
| 1 to 1.25 | Q2(b) and Q8(a), each completion item | About 2.5 to 3 | Product structure and its name, no prose |
| 2.5 | Q7(b), each short note | About 6 | 60 to 70 words |
| 5 | Every other part | About 12 | 100 to 120 words plus the key equation or mechanism |
| 10 | One full question | About 24 | Two 5-mark parts as above |
120 minutes ÷ 5 questions = 24 minutes; ÷ 2 parts = 12 minutes per 5-mark part. Keep 3 to 4 minutes for structures and arrows, leaving 8 to 9 minutes of writing × 11.5 words a minute ≈ 95 to 105 words of prose. That is about 20 words per mark, not the 30 to 40 a 150 to 200-word part would need.
CHE-06 topics that keep coming back
Grignard reactions appeared in all five official CHE-06 papers we could find before June 2026, and returned again in June 2026 as Q8(a)(v). We read the official IGNOU papers for June 2021, June 2022, December 2022, December 2023 and June 2024, then checked which topics reappeared in June 2026.
| Topic | Seen in (official papers) | Count out of 5 | In June 2026? |
|---|---|---|---|
| Grignard reagent conversions (including ring-opening of ethylene oxide to butan-1-ol) | June 2021, June 2022, December 2022, December 2023, June 2024 | 5 | Yes, Q8(a)(v) oxetane with CHβMgBr |
| Acetoacetic and malonic ester synthesis | June 2021, December 2022, December 2023, June 2024 | 4 | Yes, Q6(a) succinic acid and 2-pentanone |
| Photochemical against thermal reactions, cycloaddition symmetry | June 2021, June 2022, December 2022, December 2023 | 4 | Yes, Q4(b) thermal 2 + 2 cycloaddition |
| Free radicals (generation, stability, e.s.r. detection) | June 2021, June 2022, December 2022, June 2024 | 4 | Yes, Q4(a)(ii) chlorination of propane |
| Electrophilic aromatic substitution and orientation | June 2021, June 2022, December 2023, June 2024 | 4 | Yes, Q6(b) and Q2(b) |
| Drugs and dyes (analgesics, azo and other dye classes) | June 2021, June 2022, December 2023, June 2024 | 4 | Yes, Q7(b)(iii) analgesics and (iv) acid dyes |
| Hydroboration-oxidation | June 2021, June 2022, December 2023, June 2024 | 4 | No |
| Carbenes (structure, generation, reactions) | June 2021, June 2022, December 2023 | 3 | Yes, Q1(a) dibromocarbene |
| Aldol, Perkin and Claisen-Schmidt condensations | June 2022, December 2023, June 2024 | 3 | Yes, Q2(b)(iii) benzaldehyde with acetaldehyde |
| Biological oxidation | June 2021, June 2022, December 2022 | 3 | No |
| Benzil-Benzilic acid rearrangement | June 2021, June 2022 | 2 | Yes, Q8(b)(ii) |
| Cannizzaro reaction | June 2021, December 2022 | 2 | Yes, Q8(b)(iii) |
| Polymers (thermoplastic, thermosetting, PET) | December 2022, December 2023 | 2 | Yes, Q7(a) chain and step growth |
| Soaps and synthetic detergents | June 2021, June 2024 | 2 | Yes, Q7(b)(i) |
| HBr addition to propene, with and without peroxide | December 2023, June 2024 | 2 | Yes, Q3(b) |
Five papers is not five years. The December 2021, June 2023, December 2024, June 2025 and December 2025 CHE-06 papers were not available at IGNOU's official question paper address when we checked, so they are not counted here. If you are building a revision list, our IGNOU Solved Guess Paper section groups repeat topics by course.
Hit rate: 13 of the 15 tracked topics came back in June 2026 = 87%. Only 6 of those 13 returned as a fixed 5-mark part (ester synthesis, cycloaddition, aromatic substitution, carbenes, polymers, HBr addition). Five came only as options inside an internal choice (free radicals, drugs and dyes, detergents, Benzil-Benzilic acid, Cannizzaro), and two as single completion items worth about a mark (Grignard, aldol).
The Grignard topic, seen in all five earlier papers, came back in June 2026 as one completion item worth 1 mark out of 80 printed. A perfect repeat record does not mean a big question.
The window holds three June papers and only two December papers, so it is too small and too lopsided for a June-against-December comparison. No session pattern is claimed here.
Units and blocks June 2026 used and skipped
Blocks 2, 3 and 4 alone give exactly five complete questions, so Block 1 could have been skipped entirely in June 2026.
Q3 and Q5 come wholly from Block 2. Q1 joins Block 3 (carbenes) with Block 2 (carbonyl reactivity). Q4 is all Block 3 if you choose the propane chlorination in (a). Q7 is all Block 4 if your two notes avoid oxidation of aldehydes. That is five questions, Q1, Q3, Q4, Q5 and Q7, without a single Block 1 topic.
Blocks 2 + 3 + 4: Q1, Q3, Q4, Q5, Q7 = 5 full questions, none to spare. Q8 also reaches 9 of 10 without Block 1, since only Q8(a)(i) is Block 1. Blocks 2 + 3 alone give four full questions; Blocks 2 + 4 give three.
Block 2 alone: Q3 10 + Q5 10 + Q1(b) 5 + Q2(a) and Q2(b)(iii) about 6.25 + Q8(a)(ii) and (iii) 2 ≈ 33 of 50. No other single block comes close.
On our block mapping, three units fed nothing: Unit 2 on kinetics, Unit 7 on elimination reactions and Unit 13 on organic photochemistry itself (the thermal 2 + 2 question in Q4(b) is pericyclic, Unit 12). Unit 9 was used only by half: carbenes came in Q1(a), but nitrenes and benzynes were not asked. Unit 10 on free radicals appeared only as one option inside Q4(a).
The two skipped repeat topics do not line up with dead units. Hydroboration sits in Unit 5, which gave the HBr and hydration questions, and biological oxidation sits in Unit 8, which gave the carbonyl reductions. For those two, the signal is their exam history alone.
Topics to revise first for December 2026
Skipped topics with the longest exam history come first, then the units June 2026 left empty.
- Hydroboration-oxidation: in 4 of 5 earlier papers, missing only December 2022, and skipped in June 2026. The strongest single gap on this page.
- Elimination reactions (E1, E2, Saytzeff and Hofmann products): Unit 7 fed nothing in June 2026. Not tracked in the repeat table above, so its earlier count still needs checking.
- Nitrenes and benzynes: the unused half of Unit 9 after carbenes came in Q1(a). Also not tracked in the repeat table.
- Organic photochemistry and reaction kinetics: Units 13 and 2 gave nothing. Not tracked in the repeat table.
- Biological oxidation: 3 of 5, but last seen in December 2022 and absent from the three papers since, including June 2026. It is cooling, so it ranks below the unit gaps.
- Grignard reactions: not skipped, but now in 6 of 6 known papers. Keep the ring-opening conversions ready, even though they usually come as a small item.
How our CHE-06 answers are written and checked
Each CHE-06 answer starts from the printed question, uses the course's own terms and shows the mechanism in numbered steps. Organic Reaction Mechanism is marked on the route, not just the product, so a correct product with no intermediate rarely gets full marks.
Our chemistry writers studied the older CHE-06 papers before answering, which is how they knew that conversions from ethyl acetoacetate and Grignard ring-openings are written the way IGNOU sets them. You can read those official papers yourself in our IGNOU Previous Year Question Paper collection.
Every answer is then checked for four things: the reagent is written over the arrow, each intermediate is named (carbocation, carbanion, radical or carbene), the product is named in IUPAC form, and the stereochemistry is stated wherever the question depends on it, as it does in the cis-2-butene part of Q1.
The review is done by Sheetal Kirola, who checks wording against the IGNOU course material and confirms that answer length suits a 5-mark part. Students who find the curved-arrow notation hard can read each step as a sentence first and then as an equation.
CHE-06 solved file index, question by question
CHE-06 is a theory course with no practical file, so this index lists every June 2026 question, its block and whether its answer is on this page or in the full file. Laboratory work for B.Sc. chemistry is assessed in separate lab courses, not in CHE-06.
| Question | What it asks | CHE-06 block | Answer |
|---|---|---|---|
| Q1 | Carbenes and dibromocarbene with cis-2-butene; aldehyde against ketone reactivity | Blocks 3 and 2 | On this page |
| Q2 | Two conversions from p-nitrotoluene and benzyl alcohol; four reactions to complete | Blocks 1, 2 and 3 | Full file only |
| Q3 | Aldehyde hydrates and the most stable hydrate; Markovnikov's rule with HBr and propene | Block 2 | On this page |
| Q4 | Ester condensation or radical chlorination of propane; thermal 2 + 2 cycloaddition | Blocks 4 and 3 | Full file only |
| Q5 | Stereoselective and stereospecific reactions; reducing C=O to CHβ in acid and alkali | Block 2 | Full file only |
| Q6 | Succinic acid and 2-pentanone from ethyl acetoacetate; βCHβ against βCClβ orientation | Blocks 4 and 1 | Full file only |
| Q7 | Copolymers, homopolymers and polymer classification; two short notes from four | Block 4 (Block 2 for the oxidation of aldehydes note) | Full file only |
| Q8 | Five reactions to complete; Beckmann, Benzil-Benzilic acid or Cannizzaro mechanism | Blocks 1, 2, 3 and 4 | Full file only |
That is 8 questions in the paper: 2 solved on this page and 6 more in the full file.
Programmes that include CHE-06 Organic Reaction Mechanism
CHE-06 is a chemistry elective of IGNOU's B.Sc. under the Bachelor's Degree Programme (BSC), offered by the School of Sciences. Its assignment booklet tells students they may take elective credits from two to four science disciplines, and chemistry is one of them.
Most students who sit CHE-06 are registered in the Bachelor of Science (General) stream and take it after CHE-05 Organic Chemistry, because the mechanism course assumes you already know functional groups. Re-appearing students on the older BDP scheme also sit this paper.
If you are on the newer CBCS B.Sc. (BSCG), check your course list first, because organic chemistry there is taught under different BCHCT codes. The official CHE-06 study material, block by block, is on IGNOU's eGyanKosh CHE-06 repository.
How to get the full CHE-06 Solved Question Paper
Send a WhatsApp message to 9899436384 with "CHE-06 June 2026" and we will send the details for the complete file of all 8 answered questions. No sign-up and no form.
The full IGNOU CHE-06 Solved Question Paper includes the 2 answers on this page plus the 6 questions listed above as text only: aromatic conversions, ester condensation and radical chlorination, stereoselectivity and carbonyl reduction, ethyl acetoacetate synthesis, polymers and short notes, and the five-reaction completion with a named mechanism. The complete file comes as a PDF that reads cleanly on a phone and prints neatly on A4.
If something in an answer is unclear once you start revising, message the same number with the question number and we will explain it.
CHE-06 Organic Reaction Mechanism FAQs
What does the CHE-06 June 2026 solved question paper contain?
It contains the official IGNOU June 2026 CHE-06 Organic Reaction Mechanism paper with all 8 questions answered by our chemistry team. Each question has two 5-mark parts, so the file covers 16 parts in total. Mechanisms are written step by step with named intermediates, reagents on the arrow and IUPAC product names, in the length an examiner expects for each part.
How many CHE-06 answers are shown on this page?
Two questions are answered in full on this page: Q1 on carbenes and aldehyde reactivity, and Q3 on hydrates and Markovnikov's rule. The other six questions, Q2 and Q4 to Q8, are listed exactly as printed in the paper but without answers. Their full answers are available only in the complete file, which you can request by sending a message on WhatsApp.
How do I get the full CHE-06 Organic Reaction Mechanism solved paper on WhatsApp?
Send a WhatsApp message to 9899436384 saying "CHE-06 June 2026". We will reply with the file details and send the PDF once your order is confirmed. The complete file holds answers to all 8 questions of the paper, which means the 2 shown on this page plus the 6 questions that appear here as text only.
What is the exam pattern of the CHE-06 term-end paper?
The June 2026 CHE-06 paper is a 2-hour paper worth 50 marks. It has 8 questions of 10 marks each, and you answer any five. Every question is split into an (a) and a (b) part of 5 marks. Q4(a), Q7(b) and Q8(b) carry an internal choice, and the paper is printed in both English and Hindi.
Is CHE-006 the same course as CHE-06?
Yes. The June 2026 question paper prints the code in its three-digit form, CHE-006, but it is the same CHE-06 Organic Reaction Mechanism course of the B.Sc. Bachelor's Degree Programme. Search for either code and you reach the same paper and the same solved file.
Which CHE-06 topics repeat most often in IGNOU papers?
In the five official CHE-06 papers we read, from June 2021 to June 2024, Grignard reagent conversions appeared every time. Acetoacetic and malonic ester synthesis, free radicals, aromatic substitution, drugs and dyes, hydroboration and the photochemical against thermal comparison each appeared four times. Most of these topics returned again in the June 2026 paper, as the repeat table on this page shows.
Does CHE-06 Organic Reaction Mechanism have a practical file?
No. CHE-06 Organic Reaction Mechanism is a theory course, and its term-end paper has no practical section. B.Sc. chemistry laboratory work is assessed through separate lab courses with their own codes. That is why this page gives a question-by-question solved file index instead of a practical file index, showing each question, its block and where its answer is.
Which programme is CHE-06 Organic Reaction Mechanism part of?
CHE-06 is a chemistry elective in IGNOU's B.Sc. under the Bachelor's Degree Programme, with programme code BSC, offered by the School of Sciences. Students usually take it after CHE-05 Organic Chemistry, which covers functional groups. If you are on the newer CBCS B.Sc. (BSCG), check your course list, because organic chemistry there is taught under different course codes.
Who wrote and reviewed the CHE-06 answers?
The answers were written by our chemistry subject team after studying earlier official CHE-06 papers, and the page is authored by Prateek Talwar. Every answer was reviewed by Sheetal Kirola for accuracy, IGNOU terminology and suitable answer length. The two sample answers on this page come from the same file, so you can judge the quality before ordering.
Who wrote and reviewed this page
This page was prepared by the Unnati Educations chemistry team, which writes solved papers, guess papers and study notes for IGNOU B.Sc. learners on both the BDP and CBCS schemes.
Prateek Talwar, Academic Head, authored the page and led its paper analysis: the block share of the 80 printed marks, the finding that Blocks 2, 3 and 4 give exactly five complete questions so Block 1 could be skipped, the 13-of-15 hit rate with the split between fixed parts, choice options and one-mark items, and the December 2026 shortlist led by hydroboration and the empty Unit 7.
Sheetal Kirola reviewed the page. She checked the cis product of dibromocarbene with cis-2-butene and the singlet-carbene reasoning behind it, the hydrate equilibria for formaldehyde, acetaldehyde and acetone, the hexachloroacetone > acetaldehyde > butanone order, the secondary-carbocation route and Kharasch effect in the HBr answer, the session counts in all 15 repeat-table rows, and the 16-unit, four-block structure.